The improvement of work conditions through participatory ergonomics for reducing the risk of lower back among steel bending workers in a construction project, Bangkok
Abstract:
The objectives of this research were to study the prevalence of low back pain. and assess the risk in the lower back before and after improving work conditions by using participatory ergonomics principles of steel bending workers in a construction project in Bangkok. This study was quasi-experimental design in one sample group by measuring before and after the intervention, with a total of 10 samples that passed the inclusion criteria. The study tools included personal data questionnaire, nordic musculoskeletal questionnaire, Visual Analogue Scale (VAS) for assessing the intensity of pain sensations, and electromyography (EMG). Data were analyzed by comparing risk scores for working postures, lower back pain sensation and back muscle electrocardiogram between before and after improving work conditions using participatory the Wilcoxon signed-rank test. For the results, the sample had an average age of 30.4 ± 4.99 years, an average weight of 62.30 ± 14.43 kg, an average height of 164.20 ± 6.99 cm. All participants had no underlying diseases. The average steel bending experience was 2.80 ± 2.15 years and the average working period was 6.80 ± 0.63 days/week. Results of the design of the steel table equipment increased the height of the steel bending machine 25 cm. It made of box steel and the weight was approximately 50 kg. The prevalence of abnormalities in the skeletal system of the lower back muscles in the past 12 months before and after improving work conditions found that the lower back tissue did not change for everyone (100%). However, in the past 7 days after improving work conditions using participatory ergonomics, the prevalence of lower back muscle skeletal disorders decreased in everyone (100%). Low back pain intensity scores using the visual analogue scale (VAS) were found to be effective after improving work conditions. The sample group had a significantly lower mean low back pain score at P = .012. The results of ROM showed that the posture bent forward, stretching backward, side arch decreased with statistical significance after improving work conditions at P = .05. The results of the electrical wave measurement of the lower back muscles revealed that the average amplitude of the lower back muscles, latissimus dorsi, and muscles erector spine reduced statistically significant after improving work conditions using participatory ergonomic at P = .005. Therefore, the enterprise should apply the participatory ergonomics principles to improve work conditions in the other jobs, and also supported the occupational health promotion activities to build muscle strength for reducing the risk of musculoskeletal diseases.